硫氰酸盐光度法测定钨精矿中三氧化钨

利用新型多元素测定仪的良好线性,建立了硫氰酸盐光度法测定钨精矿中三氧化钨含量的方法。对试样的熔融条件、称样量、结果的计算方法、显色剂的配制等方面进行了优化,并用管理样和生产样品验证了分析方法的准确度和精密度。结果表明,试样用过氧化钠与碳酸钠混合熔剂熔融,熔块经EDTA(20 g/L)-乙醇(5 g/L)浸取液浸取后,铁、钙、锰、铜、镍、铋等对测定没有干扰,但铌干扰测定,可用草酸溶液消除。方法用于钨精矿中三氧化钨的测定,测定值与参考值或重量法测定值相吻合,相对标准偏差(RSD,n=6)在0.12%～0.30%之间。

Determination of tungsten trioxide in tungsten concentrate by thiocyanate spectrophotometry

A method for the determination of tungsten trioxide in tungsten concentrate was established by taking the advantage of good linearity of novel multi-element analyzer. Fusion conditions, sample mass, calculation method, chromogenic agent preparation, etc. were optimized. Method accuracy and precision were verified by management sample and production sample. The results showed that after the sample was fused by mixed fuse of sodium peroxide and sodium carbonate and the fusant was leached by EDTA (20 g/L)-ethyl alcohol (5 g/L), Fe, Ca, Mn, Cu, Ni, Bi, etc. had no interference with the determination, except for Nb, whose interference could be eliminated by oxalic acid. The proposed method has been applied to determine tungsten trioxide in tungsten concentrate. The found values were consistent with the reference value or the results of gravimetry. The relative standard deviation (RSD, n=6) was within 0.12%-0.30%.